解一元二次方程：5x²-8x=-1

解一元二次方程：5x²-8x=-1
解一元二次方程：5x²-8x=-1

解一元二次方程：5x²-8x=-1
5x²-8x+1=0
x²-8/5x+1/5=0
x²-8/5x+(16/25)-(16/25)+1/5=0
(x-4/5)²-11/25=0
(x-4/5)²=11/25
x-4/5=±1/5*根号11
x1=4/5+1/5*根号11
x2=4/5-1/5*根号11

5x²-8x=-1
5x²-8x+1=0
a=5 b=-8 c=1
代入求根公式得
x=[8±√(64-20)]/10=(4±√11]/5
所以
x1=(4+√11]/5 x1=(4-√11]/5